I have a 97 chevy s-10 blazer 4.3l v6 vortech with 137,000miles. I have started having problems with the fuel pump turning on.I started having this problem a while ago and it got worse to the point that it just dosent come on any more. When I turn the key to the on position the caution lights that should turn on for a split second then go off, dont turn on, nor do the gauges work, and the fuel pump dont prime but the vehicle will crank till the battery goes dead. I changed the fuel pump relay and both ecm batt, ecm eng fuses. What could be the problem?